I have to say that Snowball's signs, as you describe them, would make me look
first at a possible insulinoma. Low blood sugar can cause nausea and
heaving, as well as weight loss, episodes of weakness, and a bunch of other
things. You said bloodwork was done and was inconclusive. What was her
blood sugar and was it a fasting (about three hours) blood sample? If it
wasn't, I think that would be my next step.

If it is indeed insulinoma, there are certainly treatments that can help her.